Maintaining shale stability by pore plugging

Abstract

Compositions and methods for improving wellbores stability of a hydrocarbon bearing shale formation using nanoparticles to decrease swelling and plug pore throats.

What is claimed is: 
     
       1. A method of increasing shale formation stability with a water-based drilling fluid, the method comprising the steps of:
 identifying a shale formation, wherein the shale comprises Pierre, Arco China, C1, C2, C3, C4, C5, Atoka, Gumbo, Pierre, Wolfcamp, Wellington or Mancos; 
 delivering a water-based nanoparticle drilling fluid to the shale formation, wherein the drilling fluid comprises: 
 an aqueous continuous phase; and 
 one or more nanoparticles, wherein the one or more nanoparticles comprise between about 5 and about 45 weight percent nanoparticles in a size range of between about 5 and 500 nanometer and are present in a sufficient weight percent to stabilize the shale formation. 
 
     
     
       2. The method of  claim 1 , wherein the nanoparticles are selected from silica, aluminum, iron, titanium or other metal oxides and hydroxides. 
     
     
       3. The method of  claim 1 , wherein the nanoparticles comprise a size range of between 10 and 32 nanometers. 
     
     
       4. The method of  claim 1 , wherein the nanoparticles are provided into a wellbore in the form of a slug of nanoparticles in a drilling mud. 
     
     
       5. The method of  claim 1 , wherein the nanoparticles further comprise a surface active agent. 
     
     
       6. An additive composition for aqueous drilling fluids which imparts improved stability when used in drilling shale formations comprising:
 an aqueous phase comprising an effective quantity of one or more nanoparticles comprising a size range of between 5 and 500 nanometer and adapted for use in a hydrocarbon bearing shale formation selected from Pierre, Arco China, C1, C2, C3, C4, C5, Atoka, Gumbo, Pierre, Wolfcamp, Wellington or Mancos, wherein the one or more nanoparticles are between about 5 and about 45 weight percent nanoparticles and are selected from silica, aluminum, iron, titanium or other metal oxides and hydroxides wherein the nanoparticles decrease swelling and plug pore throats. 
 
     
     
       7. The method of  claim 1 , wherein the shale comprises Pierre, Arco China, C1, C3, C5, or Atoka. 
     
     
       8. The aqueous well-drilling fluid containing between about 1 and about 41 weight percent, based on the weight of the aqueous phase, of the additive composition of  claim 6 . 
     
     
       9. The additive of  claim 6 , wherein the nanoparticles further comprise one or more surface modifications. 
     
     
       10. An aqueous well-drilling fluid for hydrocarbon bearing shale formation selected from Pierre, Arco China, C1, C2, C3, C4, C5, Atoka, Gumbo, Pierre, Wolfcamp, Wellington or Mancos containing between about 1 and about 50 weight percent of a silica nanoparticles, wherein the nanoparticles are selected from silica, aluminum, iron, titanium or other metal oxides and hydroxides and the silica nanoparticles comprise between about 5 and about 45 weight percent nanoparticles in a size range of between a 5 and a 500 nanometer range and are adapted for use in shale selected from Pierre, Arco China, C1, C2, C3, C4, C5, Atoka, Gumbo, Pierre, Wolfcamp, Wellington or Mancos. 
     
     
       11. An aqueous well-drilling fluid containing
 an aqueous well-drilling fluid adapted for use in shale selected from Pierre, Arco China, C1, C2, C3, C4, C5, Atoka, Gumbo, Pierre, Wolfcamp, Wellington or Mancos; 
 wherein the aqueous well-drilling fluid comprises an aqueous phase and between about 5 and about 45 weight percent silica nanoparticles with a particle size of between 5 and 500 nm. 
 
     
     
       12. The fluid of  claim 11 , wherein the fluid comprises between 10 and about 29 weight percent silica nanoparticles, based on the weight of the aqueous phase. 
     
     
       13. The fluid of  claim 11 , wherein the nanoparticles further comprise one or more surface modifications. 
     
     
       14. The method for drilling effectively through unconsolidated shales which comprises using the aqueous drilling fluid of  claim 11  in the drilling operation. 
     
     
       15. A method of increasing shale formation stability with a water-based drilling fluid, the method comprising:
 identifying a shale formation selected from Pierre, Arco China, C1, C2, C3, C4, C5, Atoka, Gumbo, Pierre, Wolfcamp, Wellington or Mancos; 
 delivering the water-based drilling fluid to the shale formation, wherein the drilling fluid comprises an aqueous continuous phase and a slug of nanoparticles between about 5 and about 45 weight percent nanoparticles and with a particle size of between 10 and 500 nm, wherein the nanoparticles are present in a sufficient weight percent to stabilize the shale formation. 
 
     
     
       16. The method of  claim 15 , wherein the nanoparticles comprise from 5 to 40 weight percent nanoparticles in a drilling mud. 
     
     
       17. A method of increasing shale formation stability with a water-based drilling fluid, the method comprising the steps of:
 identifying a shale formation, wherein the shale comprises C1, C2, C3, C4, or C5; 
 delivering the water-based drilling fluid to the shale formation, wherein the drilling fluid comprises 
 an aqueous continuous phase; and 
 nanoparticles, wherein the nanoparticles have a particle size of between 5 and 500 nm and are present in a sufficient weight of between 0.05 and 25 weight percent to stabilize the shale formation. 
 
     
     
       18. A method of increasing shale formation stability with a water-based drilling fluid, the method comprising the steps of:
 identifying a shale formation, wherein the shale comprises Pierre, Arco China, Atoka, Pierre, Wolfcamp, Wellington or Mancos; 
 delivering the water-based drilling fluid to the shale formation, wherein the drilling fluid comprises 
 an aqueous continuous phase; and 
 one or more nanoparticles have a particle size of between 5 and 500 nm, wherein the nanoparticles are present in a sufficient weight percent of between 0.05 and 25 weight percent to stabilize the shale formation. 
 
     
     
       19. The method of  claim 18 , wherein the shale comprises Pierre, Arco China, or Atoka. 
     
     
       20. A method of increasing shale formation stability with a water-based drilling fluid, the method comprising the steps of:
 identifying a shale formation, wherein the shale comprises Gumbo; 
 delivering the water-based drilling fluid to the shale formation, wherein the drilling fluid comprises 
 an aqueous continuous phase; and 
 nanoparticles, wherein the nanoparticles are present in a sufficient weight percent of between 0.05 and 25 to stabilize the shale formation.